Magneto-electric machine



M. M. CARDELLlNO- MAGNETO ELECTRIC MACHINE. APPLICATION, map 0cT.24. 1919.

3 SHEETS-SHEET l- Jig 1 M. M. CARDELLINO. MAGNETO ELECTRIC MACHINE.

I Patented Jan. 31, 1922.

TS-SHEET 2 SHEE M. M. CARDELLINO.

MAGNEIO ELECTRIC MACHINE.

APPLICATVION, man ocT.24, 1919.

1,405,275. Patented Jan.31,1922.

3 SHEETS-SHEET 3- UNITED STATES PATENT OFFICE.

MICHELANGELO MARIA CARDELLINO, OF RACGONIGI PER CAVALLERLEONE, ITALY.

MAGNETIC-ELECTRIC MACHINE.

To all whom it may concern:

Be it known that I, MIorrELaNoELo MARIA CARDELLINO, a subject of the King of Italy, and resident of Racconigi per Cavallerleone, in the Kingdom of Italy, have invented certain new and useful Improvements in Mag neto-Electric Machines; and I dohereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention relates to magnetoelectric machines and consists in the novel arrangement of the magnetic circuits, whereby a great number of advantages are obtained, ascompared to the known machines of the same character. I

The most important 0t said advantages are the following:

(1) Maximum utilization of the magnetic flux and minimum leakage;

' (2) Magnetic circuit is kept constantly closed, assisting in the maintenance of magnetism in the permanent magnets;

(3) Windings fully independent from the rotating part; weight and size of the whole reduced as compared to the usual machines of the same efliciency; 7

(4:) Great facility of construction of the several parts and in the mounting and dismounting of the same. g V

The machine can have a large number of different applications amongwhich its employment as an ignition device in explosion engines, or as a call "bell in telephonic plants. i

In the accompanying drawings- Fig. 1. is a diagrammatic sectional View; taken through the axle of. the two rotors of a magneto electric machine embodying-my invention; 3 Y

Figs. 2 and3 are two cross-sections of the machine if taken on line H., H. of Fig. 1 (in Fig. 3 the rotors are shown turned 90 from the position shown in Fig. 2)

Fig. 4 shows one of the laminated elements forming the shoe.

' Fig. 5 shows diagrammatically the initial position of a rotor in the instant in which the longer axis of the permeable section is Specification of Letters Patent. Patented J an; 31, 1922. Application filed 00t0ber24, 1919. Serial N0. 332,873.

on the diameter perpendicular to the cenvtral line of the pole shoes when said polo shoes have an angular amplitude of 90".

Fig. 6 shows by an ideal'broken line with sharp angles a diagram of the electro-inotive force developed during a rotationof 180 accomplished by the rotor shown in Fig. 5.

Fig. 6 shows the same diagram in which the edges have been rounded as the electromotive force is not absolutely steady or absolutely zero during the intervals of variation of the flux.

Figs. 7 and 7' show respectively the ideal diagram and the diagram with rounded edgesof the other rotor with a phase displacement of 90 with respect to the rotor shown in Fig. 5.

Figs. 8 and 8 show respectively the sum of the diagram of Fig. 6 reversed and the diagram of Fig. 7 and the sum of the diagram of Fig. 6 reversed and the diagram of Fig. 7. I v

Fig. 9 shows diagrammatically the initial position of a rotor at the moment in which the longer axis of its permeable section is on the central line of the polar shoes, when the latter are of an angular amplitude of 60.

Figs. 10 and 10 show, respectively, by an ideal broken line with sharp edges and a broken line with rounded edges the diagram of theelectromotive force developed during the rotation of 180 accomplished by the rotor shown in Fig. 9.

Figs. 11 and 11? show, respectively, the

ideal diagram and thediagram with rounded edgesof the other rotor having a phase displacement of 90 with respect to the rotor shown at Fig. 9. Figs. 12 and 12 show, respectively, the sum of the diagrams Fig. 10, reversed with Fig. 11; and Fig. '10 reversed, with Fig. 11 I 1, 1, designate two permanent magnets having the form of cylindrical bars mounted in parallel relation with similar polarities on the same side. These magnets constitute the main portion of the machine.

On both ends of said magnets for nearly two-fifths of their length are placed two sets of soft iron shoe plates 3 which have an oval peripheral shape and are provided with two holes 1' for the passage of the magnets therethrough. Two guide bolts 2 of diamagnetic material passthrough holes 2 formed in said plates near their ends.

The

' .platesare also formed with two openings they are equidistant.

As it is clearly illustrated on Fig. s ot the drawing, a, portion of the outer edge of holes; 4 is clrcular and pro ect1ng, thus'formmg a proper polar shoe element. 7

the control wheels 10 are attached.

Thecomplete shoe results from piling up' a number of plates 3 like those described and illustrated in Fig. t. The nuts 6 of the guide bolts press the iron-plate shoes 3 against the projection provided on the shank 7 or a spacing sleeve.

Moreover two rotors are provided, each formed by a set of soft iron plates 8 having a lengthwise rectangular form, separated from each other by means of a thin insulating piece (like the ones used in the armature of the usual dynamo-electric machine), placed between two brass platesextending on all the length of the sets of plates. For this-purpose abrassbar can be employed which is provided with alo-ngitudinal slot for the plate set 8. The latter is placed therein and then reduced on alathe to the same diameteras the bar. The whole of the plate set is turned together with the brass bar into a cylinder having throughout. its

length a diameter slightly shorter '(b ap proximately of m/m) than that or the circular part ofthe outer edge of the holes a or distance between the poles.

On'the ends of the rotors the'journals and The axes of rotation of the rotors are parallel to the axis of the magnet and are the centers of the holes 4. As itis clearly illustrated in, Figs. 2' and 3, although the metallic section of the rotor is circular, the magnetic permeable section is a rectangle having the shorter sides substituted by arcs.

-The two rotors are exactly alike, and receive a synchronous movementfby means of the wheels 10 keyed thereon at one end; they rotate with a phase displacement of a quarter of a turn to each other; that is to say when (as shown on'Fig. 3) the core of one of the rotors (the lower one on'said figure) is 'fully in front ofthe shoes or projections 5, the brass pieces of theother rotor, onthe contrary, face the slroes in a position 90 from the other rotor. I

Two fixed bobbins l1 and 12 are mounted on insulating spools a which surround the rotors in a free space, of nearly one-fifth of the length,forme d between the two sets of plates 3'. These spools are kept centered by W0 brass plates at formed with holes to receive' the heads of they SPQolsv I h rmach erwqrksas follows: l V In the position shown on Fig. 3, the whole of the flux emanating from the polesof the two permanent magnets l is reversed on the rotor placed at the bottom of the figure, which shows the maximum magnetic section owing to the gap, which, according to the size of the figure, varies from 2% near the.

polar horns, to. 5 'm/m (at the centre of the shoes) that is about-15 times the gap of the other rotor. If however any fly lines event ually penetrate from the polar horns 'into the iron'of the upper rotor, it would be out bythe insulators placed between the plates,

which will warrant for the absence of'flux in the said rotor. r

The flux having entered thelower rotor from the north shoe (for instance from the right one in Fig; 1) passes through 'therotor longitudinally and closes at the opposite end through the small gap. of the south '(that on the leftof Fig. 1).

After of a turn both rotors have reached the positionshown on Figure 2.

In the lower one the flux'haspassed from the highest value to null, and in the other rotor from null to its highest value. It must be pointed out that during the quarter of a turn described-the magnetic circuit has remained constantly closed and with the flux all on one side by the end positions, and the flux divided between the two rotors by the middle positions. 1 V

During the following quarter of a turn the same variations in the flux take place, but in the reverse direction, between the rotors, that is from null to the maximum in the lower rotor and from maximum to null in the upper one. During the second half turn the same course is exactly repeated as described for the first half turn.

During the full turn of the rotors, four variations have then taken place, correshoe sponding to two full periods of the current 7 generated in the bobbins.

The flux is never reversed in the rotors but it issubmitted to rapid pulsations. The current which is generated is of the alternating type.

of a usual bipolar magneto-electric machine, a current of double frequency is obtained,

It is remarkable that, by the same number of turns of the rotors of this machine, and otthe double T-shaped armature The ends of the windings willbe connected 1 in such a way as to sum'up the elec'tromotive forces which are at every moment produced in both bobbins and which have the same ab= the same in both cases. In ;-the instance.

.which has been illustrated, the rotors are con-' trolled by a central wheel 13 which engages with two cogged wheels 10 keyed on the axles of both rotors which turnconsequently in the same direction.

By using the machine, wherein the opening and closing of the magnetic circuit are utilized at the same time, a single current is obtained from thetwo bobbins-united in 'series having a tension .double that of each of them, and with the frequency of two periods for each turn. I

A more than sufiicient space is reserved to said bobbins even for a double windingof high and low tension.

The amplitude of the permeable arc-of the rotor is in all cases supposed to be 60.

having the amplitudeof 90, in the moment where the main axis of the permeable section of one rotor (for instance B; see Fig. 5)

meets with the diameter perpendicular to the shoe centre (neutral line),

The electromotive force only beginsto be generated whenthe rotor has turned 15 away from the neutral line, as in said position the core of the rotor is on the point of I entering under the polar shoes. From this moment and for the space corresponding to 60 the magnetic section progressively increases and, on account ofthe uniformity of the gap, the increase may be calculated as being proportional to theangle, which is on its turn proportional to the time, by assuming a constant number of turns for the rotor.

Consequently, starting from the moment we have taken at the beginning, the electromotive force willbe null for 15, then constant and negative for the successive 60 (increasing flux). I

In the following 30 degrees'of rotation, the magnetic section does not vary, the iron core of the rotor remaining fully in front of the polar shoes. There will be a correspondinginterval during which the electromotive force is null. As the rotation proceeds still further, the magnetic section (and consequently the flux)" decreases according to a law which is uniform as to the time, for the space of 60, so that a constant, and positive electromotive force is generated.

After the exit from the shoe, the iron-core of the rotor, turning on an angle of 15 in the zone of zero flux, comes back to the starting position. In the corresponding interval there is no electromotive force at all. The rotor has described half a turn (180).

I have graphically illustrated (Figs. 6 and 6) what has been said, taking into consideration the fact that in practice, on account of secondary phenomena, the electromotive force will neither be absolutely constant nor void in the said intervals; therefore near the theoretic line with sharp angles, I have drawn a second line with connections and bends so as to approach theform which is practically assumed by the current.

The synchronous working of the other rotor of the machine shall be now fully described (see Figs. 7 and 7).

At the starting moment, when the first rotor (B) has stillits axis on the neutral line, the second rotor (B) was at 90', that is to say with the longest axis of the permeable section on the middle line of the shoes. Upon a rotation of 15 no electromotive force is generated, the flux remaining constant; but as soon as the iron of the sec- 0nd rotor begins to pass the pole shoes, a positive and constant electromotive force is generated which is maintained for the space of. 60. We consider firstly the case of shoes 5 I Then for a space of 30 the electromotive force is null, B being outside the flux, and for the space of the successive 60 the electromotive force is negative and constant; after 15 of electromotive force null the rotor is again in the starting position (half a turn of the rotor).

- B reversing the connection of the bobbin heads it is possible to obtain from the two electromotive forces generated at the same moment, and having the same absolute value but opposite polarities, a double electromotive force having the form shown on Fig. 8 resulting from the sum of the 7 with the-6 reversed. The maximum of electromotive force resulting from the said addition is reached after a rotation of 45 from the starting position. In relation to the shoes, both rotors, when in'the position of maximum of electromotiveforce, have the iron half facing, half away from the flux, Tone entering'and the other moving away from the same.

Considering now the case of polar shoes of theamplitude of 60, that is to say of the same amplitude of the permeable arc of the rotors, we assume the same beginning for the times and for the angles and examine the rotor B (see Fig. 9 and the graph ofFigs. 10and'10 I I Uponarotation (if 30 the. electromotive force is null. For the successive 60 the electromotive force is negative and constant, but there is no more interval of electromotive force null, because the iron comes immediately out from the shoe and generates positive electromotive lforce for a further space of 60.

There is then a rotation of 30 in a neutral zone (the corresponding electromotive force being null), before coming back to the starting position. Let us see what happens during the same time as to the second rotor B (Figs. 11 and 11).

At the beginning of the time the flux is maximum and, when the rotation is started, a positive electromotive force is immediately generated which remains constant and of-the samepolarity for 60. A rotation'of 60 takes place then in a neutral zone with a corresponding interval of electromotive force null. r

In the successive 60 the electromotive force is negative and constant, returning thus to the starting position.

Here also the connections can be suitabl reversed in ordergto obtain the maximum efficiency of electromotive f0rce.- V

Figs. '12 and 12? show the electromotive force resultin'g from the composition of the '11 with the 10 reversed." It must be. remarked that, though the maximum ofthe electromotive forces produced by the two bobbins be respectively displaced of 60. for

thefirstrotor and of for the second rotor from the origin of the angles the maximum of electromotive force resulting is still produced at lfroni the origin.

In relation to the shoes, the maximum of resulting electromotive force is obtained when the permeable arc of the first rotor-B has entered the 15 zone,that is to say for 11- of the amplitude, and when the permeable are of the rotor Bhas passed 45,thatis of- V In thecase 0 f shoes of 90 and the permeable arc of the rotor also of 90, there will be no moreinterval of .null electromotive Eforce.

'lVhat I claim is: 1. .In a magneto electric machine delivering pulsating current, one or more rectilinear permanentmagnets, and pole shoes con- 7 nected thereto, in combination with elongated cylindrical rotors each comprising a cylinder of diamagnetic' material having a longitudinal slot, and a bundle of plates mounted in said slot, and means for rotating the rotors. j v 7 "2. In a magneto electric machine delivering pulsating current, one or'more rectilinear permanent magnets, pole shoes for said magnets, and two rotors each comprisinga cylinder :of 'dia-magnetic material having a longitudinal slot therethrough, and insulated plates in saidslot, and means to'synchronously rotate said rotors in orthogonal 1 relation. I

-3. In a magneto electricmachine,parallel straight permanent-magnets, armatures disposed in planes at right angles to the plane of the magnets,pole shoes connecting like polesof said magnets, and windings between the poles of unlike sign and embracing the middle of said armatures; Y

4. Ina magneto electric machine, a plu rality of straight permanent magnets, lami nated pole shoe elements at the ends or said magnets,windings included between theele- V posite ends of said bars, windings included between said groups, said plates having alined perforations'forming pole shoes, said perforations being in orthogonal relation to the plane of the bars, rotors pa'ssing through 5 said perforationsand-windings, and means to rotate said armatures while malntaining angular displacement.

In a magneto electric machine, a field element comprising a plate having perfora- 1 tions" for the reception of permanent mag;

nets and perforations in orthogonal rela tion thereto' for armatures, the latter perforations' configured to form pole shoes. 1

of iron plates, means to secure the sets to gether in spaced relation, windings held betweenthe sets of plates, said plates having two sets of alined perforations displaced 7. In a magneto electric machine-two sets bar magnet s'in one set ofperforations and cylindrical armaturesin the 'other set of perforations, said armatures each comprising a cylinder of d1a-magnet1cmater1al havinga longitudinal slot, and insulated lam'inationsfilling said slot. a Intestimony that I claim the vforegoing as my invention, I have si v MICHELANGELO MARIA- CARDELLlNOaf gned 'my name. i 

